Polarization-Independent Optical Broadband Angular Selectivity

Generalizing broadband angular selectivity to both polarizations has been a scientific challenge for a long time. Previous demonstrations of the broadband angular selectivity work only for one polarization. In this paper, we propose a method that can achieve polarization-independent optical broadband angular selectivity. Our design is based on a material system consisting of alternating one-dimensionally anisotropic photonic crystal (1D PhC) stacks and half-wave plates. 1D PhC stacks have an angular photonic band gap for p-polarized light and half-wave plates can convert s-polarized light to p-polarized light. By introducing alternating 1D PhC stacks and half-wave plates, we predict that one can achieve a central transmission angle at normal incidence and an angularly selective range of less than 30° across the whole visible spectrum.